JPH03186168A - Gas extraction device of absorption type refrigerating machine - Google Patents

Abstract

PURPOSE:To restrain the wasteful consumption of cold water and reduce the cost of apparatus by providing a device which detects changes in the liquid level in a U shape seal tube leading from a gas extraction tank to an evaporator. CONSTITUTION:A U shape seal tube 17 connects a gas extraction tank 12 and an evaporator 5 and its tips on the evaporator side is connected to an overflow tank 16. Therefore, the refrigerant is supplied into the U shape seal tube 17 when the refrigerant in the seal tube 17 is run out and the pressure stays constant. A float switch 15 of a detector which detects changes in the liquid level in the U shape seal tube 17 is installed at a lower position of the U tube 17, for more detail, at a position h/2 below the balancing height h during shut down of the apparatus. Thereby, the capacity of the gas extraction tank is efficiently utilized to the maximum extent, wasteful consumption of cold water is restrained, and the cost of the apparatus is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an extraction device for an absorption refrigerating machine, and in particular to an absorption device suitable for reducing the cost of a device for discharging non-condensable gas generated inside a cycle to the outside. This invention relates to an air extraction device for a type refrigerator.

[Conventional technology] The prior art will be explained with reference to FIG.

FIG. 4 is a cycle system diagram showing the configuration of a membrane air-cooled absorption refrigerator.

The cycle of the air-cooled absorption refrigerator shown in FIG. Exchanger 7, solution circulation pump 8, refrigerant circulation pumps 9a, 9b, and air-cooled condenser 3. It is composed of a fan 10 that blows air to cool the air-cooled absorber 4.

To explain the functions of each component, in the high-temperature regenerator 1, a low-concentration solution (usually brominated Here, the lithium aqueous solution is heated to boiling and separated into a highly concentrated solution and water vapor. This water vapor is led to the low-temperature regenerator 2 through piping, and the low-temperature concentrated solution sent through the low-temperature liquid-liquid heat exchanger 6 is heated and boiled by the solution circulation pump 8 . The water vapor generated here is led to the air-cooled condenser 3, where it is condensed and becomes a refrigerant.

The relatively high temperature water condensed in the low temperature regenerator 2 also flows down into the air-cooled condenser 3 and is cooled to become a refrigerant.

On the other hand, in the air-cooled absorber 4, the high-concentration solution generated by the high-temperature regenerator 1 and the low-temperature regenerator 2 is cooled by the high-temperature liquid-liquid heat exchanger 7 or the low-temperature liquid-liquid heat exchanger 6, and then circulated through the solution circulation. It is circulated and distributed over the heat transfer tube group of the air-cooled absorber 4 by the pump 8 .

At this time, the refrigerant that is fed through the refrigerant pipes 20 by the refrigerant circulation pump 9b and sprayed by the spray device 21 evaporates onto the heat transfer tube group 5a in the evaporator 5 that communicates with the air-cooled absorber 4.
The generated water vapor is absorbed by the solution sprayed into the air-cooled absorber 4, and the concentration of the solution decreases. Here, the above refrigerant is transferred from the air-cooled condenser 3 to the evaporator 5 by the refrigerant circulation pump 9a.
The refrigerant is temporarily stored in a refrigerant tank 11 located at the bottom of the refrigerant tank 11.

The diluted solution is returned to high temperature regenerator 1 and low temperature regenerator 2.
and the cycle completes.

The heat balance on the cycle is such that the sum of the amount of heat for heating the solution in the high-temperature regenerator 1 and the amount of heat of evaporation taken in from the cold water in the evaporator 5 is carried out of the system by the cooling air in the air-cooled condenser 3 and the air-cooled absorber 4. equal to the amount of heat generated.

Next, we will explain the air extraction device necessary to maintain the cycle and achieve the desired performance.

It is a well-known fact that the presence of non-condensable gas in the air-cooled absorber 4 impedes absorption capacity.

Therefore, the extraction system generally includes a system that collects non-condensable gas on the low pressure side of the air-cooled absorber 4 into the air-cooled condenser 3 on the high-pressure side, and a system that discharges the non-condensable gas in the air-cooled condenser 3 to the outside of the cycle system. It consists of a system.

The above system utilizes the suction performance of the solution circulation pump 8 to suck in non-condensable gas from the air-cooled absorber 4 together with the solution, passes through the high-temperature regenerator and the low-temperature regenerator 2, and collects the solution in the air-cooled condenser 3. It is the same system as the circulatory system.

On the other hand, in the system described later, an air bleed tank 12 disposed in contact with a refrigerant tank 1 and an air-cooled condenser 3 are connected by a steam pipe 22, and the refrigerant in the refrigerant tank 11 is used to
is maintained at a low temperature, and the temperature difference between the condenser 3 and the refrigerant tank 11 is used as a driving force to transport water vapor and accumulate non-condensable gas in the bleed tank 12 along with the water vapor. Further, when the non-condensable gas in the bleed tank 12 reaches a predetermined pressure or higher, the pressure is detected and the cold water ejector 3 discharges the non-condensable gas together with the cold water through the pipe 23 to the outside of the cycle system.

Here, the pressure in the bleed tank 12 is at most the pressure of the air-cooled condenser 3, and as it approaches the pressure of the air-cooled condenser 3, it becomes difficult to collect non-condensable gas. It is considered to operate 13.

In any case, the pressure inside the bleed tank 2 is at most several tens of mHg, and as an effective means of detecting this low pressure, the bleed tank 12 and the condenser 3 shown in FIG.
There is a device in which a U-shaped liquid seal tube 14 is disposed between the tube and the float switch 5 to detect changes in the liquid level within the tube. That is, when non-condensable gas accumulates in the bleed tank 12 and the internal pressure increases, the liquid level in the U-shaped liquid seal tube 14 is pushed down, so that the float switch 15 can be operated.

Although this means is the simplest, it is often used because it is a reliable means for detecting the differential pressure between the air-cooled condenser 3 and the bleed tank 12.

[Problems to be Solved by the Invention] The problems in the above-mentioned prior art will be explained with reference to FIG.

FIG. 5 is a diagram explaining the principle of conventional air extraction technology, where the horizontal axis is the temperature ta of the cooling air (outside air) of the air-cooled condenser and air-cooled absorber, and the vertical axis is the air-cooled condenser and air-cooled absorber. The solid line is the pressure P of the air-cooled condenser.
, the broken line indicates the pressure P^R3 of the air-cooled absorber.

As is clear from Fig. 5, the condenser pressure P CON has a steep slope upward to the right with respect to the absorber pressure P ABS;
The absorber pressure P ABS does not have much dependence on the cooling air temperature t&. This is also a characteristic of absorption refrigerators.

Therefore, in the prior art bleed tank pressure sensing method, if the cooling air temperature t& changes, for example if t& falls, the float switch 15 will also operate at a lower pressure. For this reason, when the cooling air temperature ta is low, the cold water ejector 13 frequently operates and consumes cold water, making the air extraction system inefficient.

In general, the air extraction device plays an important role when the cooling air temperature t1 is high and the cycle temperature becomes high, and from this point of view as well, operation at a low cooling air temperature ta is not preferable.

The present invention has been made in order to solve the above-mentioned problems in the conventional technology, and utilizes the capacity of the extraction tank to the maximum extent to suppress wasteful consumption of cold water.The present invention is also simple and reduces costs. The purpose of this invention is to provide an air extraction device for a liquid absorption refrigerator.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the first invention related to the extraction device for an absorption refrigerator of the present invention includes a regenerator, an air-cooled condenser, an evaporator, and an air-cooled absorber. , an air bleed device for an absorption refrigerator comprising a solution heat exchanger, a solution pump, a refrigerant pump, and a piping system operatively connecting these, and a bleed tank in contact with a refrigerant tank connected to the evaporator, A bleed tank disposed in contact with the refrigerant tank and the evaporator are connected by a U-shaped liquid seal tube, and the U-shaped liquid seal tube is provided with means for detecting changes in the liquid level within the tube. It is.

More specifically, the evaporator is provided with an overflow tank for temporarily storing the refrigerant flowing down the inner wall of the evaporator, and the evaporator side pipe end of the U-shaped liquid seal pipe is connected to the overflow tank.

Also, the evaporator side tube end of the U-shaped liquid seal tube.

Some are open to the flow path of the refrigerant flowing down in the evaporator.

Furthermore, in order to achieve the above object, the structure of the second invention related to the extraction device of the absorption chiller of the present invention includes a regenerator, an air-cooled condenser, an evaporator, an air-cooled absorber, a solution heat exchanger, and a solution heat exchanger. In an air bleed device for an absorption refrigerator, which includes a pump, a refrigerant pump, and a piping system that operatively connects these, and has an air bleed tank in contact with a refrigerant tank connected to the evaporator,
connecting a bleed tank disposed in contact with the refrigerant tank and a lower tank of the air-cooled absorber with a U-shaped liquid seal pipe;
The U-shaped liquid seal tube is provided with means for detecting changes in the liquid level within the tube.

Furthermore, the U-shaped liquid seal pipe in each of the above configurations is equipped with a solenoid valve.

Additionally, the technical idea behind the development of the present invention is as follows.

When detecting the pressure inside the bleed tank using the differential pressure between the air-cooled condenser and the air-cooled condenser, as explained in the prior art described above,
Since the pressure of the air-cooled condenser changes significantly depending on the outside air conditions of the device, there is a drawback that constant pressure cannot be detected.

In order to eliminate this drawback, it is preferable to detect the pressure difference between the pressure inside the device and the location, which is relatively independent of operating conditions. In this case, the part where the internal pressure changes the least is the evaporator, and the pressure may be detected by the change in the liquid level in the U-shaped liquid seal pipe between the evaporator and the bleed tank.

[Operation] The operation of the above technical means will be explained with reference to FIG. 6.

FIG. 6 is a diagram explaining the origin of the air bleed technology of the present invention, and corresponds to the conventional technology shown in FIG.

The pressure inside the evaporator is expressed as PEV^, which is approximately several mHg during normal operation, and is considered to be constant, almost unaffected by the cooling air temperature t&. On the other hand, the pressure in the bleed tank is approximately equal to the vapor pressure at which the refrigerant tank temperature is determined, which is equal to the absorber pressure P ABS (and P ABS is P
Equivalent to EV^).

In such a system, if the float switch associated with the liquid level change detection means in the U-shaped liquid seal pipe is installed at a height of h/2 minutes below the equilibrium position when the device is stopped, the condenser pressure P CON and Absorber pressure P When a pressure rise corresponding to the differential pressure head with respect to ABS occurs in the bleed tank (that is, non-condensable gas is accumulated by the head), the float switch is activated and the bleed tank clears the non-condensable gas. Detects that it is full.

The dashed line in FIG. 6 indicates the pressure at which the float switch operates. Let ta' be the cooling air temperature at the intersection of the float switch operating pressure line and the condenser pressure P CON line.

Because the internal pressure of the extraction tank does not exceed the condenser pressure PCON due to the accumulation mechanism of non-condensable gas, the water system is
>ta', the float switch operates.

Therefore, at a low cooling air temperature t&, there is no longer a problem in which the flow 1 to switch frequently detects the liquid level and the cold water ejector operates, which increases the amount of cold water consumed, as in the prior art system.

[Embodiments] Hereinafter, each embodiment of the present invention will be described with reference to FIGS. 1 to 3.

First, an embodiment of the invention will be described with reference to FIGS. 18 and 2.

The king diagram is a configuration diagram of an air extraction device section of an air-cooled absorption refrigerator according to an embodiment of the present invention. In the figure, parts with the same reference numerals as those in FIG. 4 are equivalent to those in the prior art, and therefore their explanations will be omitted. Furthermore, since the basic configuration of the air-cooled absorption refrigerator in this embodiment is the same as that shown in FIG. 4, the explanation of the second structure and its operation will be omitted, and the embodiment will be described here with respect to the air extraction system. FIG. 1 shows an air extraction device around the refrigerant tank 1.

In FIG. 1, 16 is an overflow tank that temporarily stores the refrigerant flowing down the inner wall of the evaporator 5, 17 is a U-shaped liquid seal pipe that connects the bleed tank 12 and the overflow tank 16, and 18 is a U-shaped liquid seal pipe for connecting the bleed tank 12 and the overflow tank 16. This is a solenoid valve provided in the letter-shaped liquid seal pipe 17.

Next, the configuration and function of the air extraction device will be explained.

A refrigerant tank 11 is formed at the bottom of the evaporator 5.
A bleed tank 2 is disposed in contact with this refrigerant tank 11.

The refrigerant liquid is sent from the bottom of the refrigerant tank 1 to the upper part of the evaporator 5 via the refrigerant pipe 20 by the refrigerant circulation pump 9b.
The refrigerant is sprayed from the spray device 21 onto the heat transfer tube group 5a in the evaporator, and the refrigerant flows down the wall of the evaporator 5[refrigerant tank]1 to cool the outer wall of the bleed tank 12.

On the other hand, a U-shaped liquid seal pipe]-7 connecting the bleed tank 12 and the evaporator 5 is provided, and the end of the pipe on the evaporator side is connected to the overflow tank 16.

In this way, the refrigerant in the U-shaped liquid seal pipe 17 is replenished without running out, and the pressure is also maintained constant. A float switch 15, which is a means for detecting a change in the liquid level in the U-shaped liquid seal tube 7, is located below the upright portion of the U-shaped tube, specifically at a height of 11 mm from the equilibrium position when the device is stopped.
72 minutes, installed below. Here, h is the differential pressure head between the condenser pressure P CON and the absorber pressure PABS (see FIG. 6).

The pressure in the bleed tank 12 increases and the U-shaped liquid seal pipe 17
When the liquid level inside drops, the float switch 15 is activated. In addition, a solenoid valve ]-8 is provided in the middle of the U-shaped liquid seal pipe 17, and when the refrigerator is stopped, the pressure balance is collapsed and the refrigerant flows through the U-shaped liquid seal pipe 17 into the tank 2.
closed to prevent backflow.

The operation of the cycle of the air-cooled absorption refrigerator is similar to the prior art described above with reference to FIG.

The operation of the air extraction device will be explained with reference to FIG. 4 and FIG.

When non-condensable gas exists in the air-cooled absorber 4, the non-condensable gas is transferred from the air-cooled absorber 4 on the low pressure side to the air-cooled condenser 3 on the high pressure side.
be gathered to. That is, in the same system as the solution circulation system, the solution circulation pump 8 sucks incondensable gas together with the solution from the air-cooled absorber 4, passes through the high-temperature regenerator and the low-temperature regenerator 2, and collects it in the air-cooled condenser 3. Next, using the temperature difference between the air-cooled condenser 3 and the refrigerant tank 11 as a driving force, water vapor is transported from the air-cooled condenser 3 to the bleed tank 12 through the steam pipe 22, and the contained non-condensable gas is accumulated in the bleed tank 12. .

Furthermore, the non-condensable gas in the bleed tank 12 has a differential pressure head h (sixth
When the pressure corresponding to (see figure) is accumulated, the float switch 15 is activated and it is detected that the bleed tank is full of non-condensable gas. As a result, the cold water ejector 13 shown in FIG. 4 operates to discharge the non-condensable gas along with the cold water to the outside of the cycle system through the pipe 23.

In the bleed air system of this embodiment, the float switch 15 operates when the cooling air temperature is in the range ta>i', so unlike the bleed air system of the prior art, the float switch frequently raises the liquid level at low cooling air temperatures. When detected, the cold water ejector operates, eliminating problems such as high cold water consumption.

According to this embodiment, the capacity of the bleed tank can be utilized as effectively as possible, and wasteful consumption of cold water can be avoided. Also, U
Since the shaped liquid seal tube only needs to be routed around the refrigerant tank, it has the effect of reducing costs.

Next, FIG. 2 is a configuration diagram of an air extraction device section of an air-cooled absorption refrigerator according to another embodiment of the present invention. In the figure, parts with the same reference numerals as in FIG. 1 are the same parts as in the previous embodiment, so their explanation will be omitted. Further, the basic configuration of the air-cooled absorption refrigerator in this embodiment is the same as that shown in FIG. 4.

The embodiment shown in FIG. 2 differs from the embodiment shown in FIG. 1 in that the overflow tank 16 as shown in FIG. Wall part 1 of the refrigerant tank 11 which is a flow path for the refrigerant liquid flowing down inside] -
It has an opening at a. Thereby, refrigerant liquid is constantly supplied to the U-shaped liquid seal pipe 17A.

According to the embodiment shown in FIG. 2, the same effects as those described in the embodiment shown in FIG. 1 can be expected.

Next, an embodiment of the second invention will be described with reference to FIG.

FIG. 3 is a configuration diagram of an air extraction device section of an air-cooled absorption refrigerator according to still another embodiment of the present invention. In the figure, parts with the same reference numerals as those in FIG. 4 are equivalent to those in the prior art, and therefore their explanation will be omitted. Further, the basic configuration of the air-cooled absorption refrigerator in this embodiment is the same as that shown in FIG. 4.

The difference between the embodiment shown in FIG. 3 and the embodiments shown in FIGS. 1 and 2 is that one end of the U-shaped liquid seal pipe 17B is connected to the air-cooled absorber
The lower tank 4a is connected to the lower tank 4a.

Generally, the air-cooled absorber 4 is communicated with the evaporator 5 and maintained at the same pressure, so the embodiment shown in FIG. 3 is expected to have the same effects as the previous embodiments. However, in the case of this embodiment, the refrigerant condensed in the bleed tank 12 and the solution from the air-cooled absorber 4 exist in the U-shaped liquid seal pipe 17B, causing a concentration difference in the pipe and causing corrosion. is likely to occur. In order to prevent this, for example, the discharge port of the solution wi ring pump 8 may be bypassed and a portion of the solution may be transferred to the bleed tank 12.
A piping line 19 leading to the U-shaped liquid seal pipe 17B is provided.
What is necessary is to form a very small amount of flow within the tube to suppress the occurrence of concentration differences.

[Effects of the Invention] As explained in detail above, according to the present invention, the capacity of the bleed tank can be utilized as effectively as possible to suppress wasteful consumption of cold water, and the device is simple and costs can be reduced. A bleed device for an absorption refrigerator can be provided.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an air bleed device section of an air-cooled absorption refrigerator according to an embodiment of the present invention, and FIG. 2 is a block diagram of an air bleed system section of an air-cooled absorption refrigerator according to another embodiment of the present invention. Fig. 3 is a block diagram of the bleed device section of an air-cooled absorption refrigerator according to still another embodiment of the present invention, and Fig. 4 is a cycle diagram showing the structure of an intra-membrane air-cooled absorption refrigerator. The system diagram, FIG. 5 is a line diagram explaining the principle of the conventional air bleed technology, and FIG. 6 is a line diagram explaining the principle of the air bleed technology of the present invention. 1... High temperature regenerator, 2... Low temperature regenerator, 3... Air-cooled condenser, 4... Air-cooled absorber, 4a... Lower tank, 5... Evaporator, 6... Low temperature liquid heat exchanger, 7...
・High-temperature liquid-liquid heat exchanger, 8...solution @ ring pump, 9a,
9b... Refrigerant circulation pump, 11... Refrigerant tank, l
la...wall, 12...bleeding tank, ], 5...
Float switch, 16... Overflow tank, 17
．． 17A, 17B... U-shaped liquid seal tube, 18...
solenoid valve.

Claims (1)

[Scope of Claims] 1. A regenerator, an air-cooled condenser, an evaporator, an air-cooled absorber, a solution heat exchanger, a solution pump, a refrigerant pump, and a piping system operatively connecting these; In an air bleed device for an absorption refrigerating machine in which a bleed tank is provided in contact with a refrigerant tank to be connected, the bleed tank provided in contact with the refrigerant tank and the evaporator are connected by a U-shaped liquid seal pipe, 1. An air extraction device for an absorption refrigerator, characterized in that a U-shaped liquid seal tube is provided with means for detecting a change in the liquid level within the tube. 2. A regenerator, an air-cooled condenser, an evaporator, an air-cooled absorber, a solution heat exchanger, a solution pump, a refrigerant pump, and a piping system for operatively connecting these, and in contact with a refrigerant tank connected to the evaporator. In an air bleed system for an absorption chiller equipped with an air bleed tank, the air bleed tank disposed in contact with the refrigerant tank and the lower tank of the air-cooled absorber are connected by a U-shaped liquid seal pipe, and the U-shaped 1. An air extraction device for an absorption refrigerator, characterized in that a liquid seal tube is provided with means for detecting a change in the liquid level within the tube. 3. The evaporator is provided with an overflow tank for temporarily storing the refrigerant flowing down the inner wall of the evaporator, and the evaporator side pipe end of the U-shaped liquid seal pipe is connected to the overflow tank. 1. The extraction device for an absorption chiller according to 1. 4. The air extraction device for an absorption refrigerator according to claim 1, wherein an end of the U-shaped liquid seal tube on the evaporator side is opened to a flow path for refrigerant flowing down in the evaporator. 5. The air bleed device for an absorption refrigerator according to any one of claims 1 to 4, characterized in that the U-shaped liquid seal pipe is equipped with a solenoid valve.